Clinical investigation of HIV-induced disease requires the ability to study at-risk and HIV-infected human subjects. These clinical studies can span a broad spectrum including bench to bedside translational research, epidemiological and behavioral studies and implementation and dissemination science. The Clinical and Population Sciences Core is specifically dedicated to enabling translational research within the UCSF-GIVI CFAR. To achieve this goal, this Core pursues four specific aims including: Aim 1: To provide expertise in the clinical and population sciences related to HIV/AIDS research via consultation regarding the conception of research questions, study design, sources of data on human subjects, data management, biostatistical analysis, and interpretation of data; Aim 2: To manage unique prospective observational cohorts of HIV-infected subjects in both San Francisco (the SCOPE cohort) and Africa (the Uganda-based UARTO and ISS Clinic Cohorts) that provide basic and translational researches with a diverse array of biological specimens and data from subjects who are well-characterized in terms of epidemiologic, clinical, laboratory and behavioral parameters; Aim 3: To offer a platform for the efficient conduct of newly proposed prospective human subjects studies; Aim 4: To mentor early stage investigators in the conduct of research involving human subjects. Overall, the Clinical and Population Sciences Core provides multiple researchers with an efficient centralized resource that helps circumvent the substantial cost and time burden inherent in the complexity of human subjects research. Evidence of the utility of the Core's approach in the current funding cycle is evidenced by the fact that 251 users have accessed the core, 19,568 biological specimens have been distributed, and 108 papers have been published by Core users. In this proposed renewal, the Core's overall objectives remain unchanged, however activities and resources in the Core will be refined based on the new research initiatives being launched by UCSF-GIVI CFAR investigators.